Tritium labeling of organic compounds by HNaY zeolite catalyzed exchange with tritiated water and their analysis by tritium NMR

Abstract

The principle of using small amounts of high activity water in an otherwise water-sensitive catalytic system has previously been employed with Lewis acid labeling catalysts. The advantages of such procedures include the relative simplicity of handling tritiated water and its low cost compared with alternatives such as tritium gas and tritiated benzene. No vacuum techniques are necessary, and the activity of the product is limited only by the specific activity of the small aliquot of HTO used as isotope source. The reactants, organic (0.1 g), zeolite (25 mg), and tritiated water (5 ..mu..L, 40 mCi/mL) were sealed in a glass ampule and heated to 175/sup 0/C for the desired reaction time. Products were analyzed by radiogas chromatography and /sup 3/H NMR spectroscopy. The results show that the procedure represents a highly efficient method of tritiation of most aromatic compounds. Since the molar ratio of organic compound to water was high, equilibrium represents virtually 100% incorporation of the tritium utilized in the experiment.